Changes in thermal energy provide evidence that a chemical reaction has occurred. Which of the following BEST describes a chemical reaction
in which energy is released?
Select one:
Exothermic reaction.
Reversible reaction
Physical reaction
Endothermic reaction.

Transportation is the largest single source of air pollution in the united states. air pollution can harm the environment and human health. which technology could offer a solution to this problem? mufflers that reduce noise motors that run on electricity tires that improve gas mileage

Joe shines white light into a bowl half full of water at an angle of incident of 27.5°. calculate the angle of refraction in the water given the indices of refraction for air and water are 1.00 and 1.36, respectively.

An atom of which element reacts with an atom of hydrogen to form a bond with the greatest degree of polarity ?